Matthew Henry Commentary4:29-32 Filthy words proceed from corruption in the speaker, and they corrupt the minds and manners of those who hear them: Christians should beware of all such discourse. It is the duty of Christians to seek, by the blessing of God, to bring persons to think seriously, and to encourage and warn believers by their conversation. Be ye kind one to another. This sets forth the principle of love in the heart, and the outward expression of it, in a humble, courteous behaviour. Mark how God's forgiveness causes us to forgive. God forgives us, though we had no cause to sin against him. We must forgive, as he has forgiven us. All lying, and corrupt communications, that stir up evil desires and lusts, grieve the Spirit of God. Corrupt passions of bitterness, wrath, anger, clamour, evil-speaking, and malice, grieve the Holy Spirit. Provoke not the holy, blessed Spirit of God to withdraw his presence and his gracious influences. The body will be redeemed from the power of the grave at the resurrection day. Wherever that blessed Spirit dwells as a Sanctifier, he is the earnest of all the joys and glories of that redemption day; and we should be undone, should God take away his Holy Spirit from us.

Hebrews 10:29How much more severely do you think one deserves to be punished who has trampled on the Son of God, profaned the blood of the covenant that sanctified him, and insulted the Spirit of grace?

Treasury of Scripture

And grieve not the holy Spirit of God, whereby you are sealed to the day of redemption.